CVE-2021-30913

NVRAM modification via SoftwareUpdate permissions flaw

Published Aug 24, 2021 · Updated Aug 3, 2024

Permissions bypass in Apple macOS Big Sur before 11.6.1 and Monterey before 12.0.1 allows local users to edit NVRAM variables. The SoftwareUpdate component applies insufficient restrictions when an unprivileged application requests an NVRAM variable change, but Apple has not disclosed the exact code path or failed permission check. Execution of an unprivileged local application is required; the established consequence is unauthorized NVRAM modification, with no further impact established by Apple.

CVSS severity5.5
Medium
EPSS probability1.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Permissions bypass in Apple macOS Big Sur before 11.6.1 and Monterey before 12.0.1 allows local users to edit NVRAM variables. The SoftwareUpdate component applies insufficient restrictions when an unprivileged application requests an NVRAM variable change, but Apple has not disclosed the exact code path or failed permission check. Execution of an unprivileged local application is required; the established consequence is unauthorized NVRAM modification, with no further impact established by Apple.

The record

CVE
CVE-2021-30913
Published
Aug 24, 2021
Updated
Aug 3, 2024
Vendor
Apple
Product
macOS
Classifications
Unavailable
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <11.6
  2. Affected versionversion=unspecified <12.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Apple · macOSversion=unspecified <11.6; version=unspecified <12.0

Published CVSS scores

4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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